As we have seen, the Latin alphabet grew indirectly out of
the Greek alphabet, since it is derived from the Etruscan alphabet, which
itself was an adaptation of the Greek alphabet, which was itself an adaptation of
the Phoenician one. This original adaptation was the most significant one since,
for instance, at the time letters were added for vowels, since the Phoenician
alphabet only encoded consonant sounds.

In addition to that primary influence of the Greek
alphabet on the Latin one, there were additional ones that came later, when
Romans were in close contact with Greek speakers and their language after the
former conquered the latter and started to introduce large numbers of Greek
words into Latin. In particular, Ancient Greek had some sounds that Latin did not
have and when the Romans borrowed words from Greek that had sounds that did not
exist in Latin, they had two options. One of them was to borrow those Greek letters.
That is how the letters 〈Z〉 and 〈Y〉 entered Latin, though they remained
peripheral additions only used to write words of Greek origin. The other
solution was to modify existing Latin letters to represent the Greek sounds.
They did that for four Greek sounds by adding an 〈H〉 to a similar sounding Latin
letters. They did that to the aspirated Greek consonant sounds that did not
exist in Latin. The latter solution resulted in the following digraphs, or two-letter combinations, to
represent single sounds that were represented by single Greek letters: 〈CH〉, 〈TH〉,
〈PH〉, and 〈RH〉, as we shall see below.

Greek letter

Latin
transliteration

Π π

(pi)

[p]

P

Φ φ

(phi)

[pʰ]

PH

Many
English words have the letters 〈z〉 and 〈y〉, in words such as zero and myth. In many cases, these words come from Greek. However, because
English appropriated these two letters to write English sounds during the
Middle Ages, not all of them do. The letter 〈y〉 originally represented only
vowels in Greek and Latin and if an English word has a vocalic 〈y〉 that is a
sure sign that the word comes from Greek. The sound of this letter is the sound
[ɪ]
or [aɪ̯]
in Modern English. But the letter 〈y〉 is also used in English to represent the
consonant sound [j], as in the word you
[ˈju],
and these words are never of Greek origin.

Spanish
too appropriated the letters 〈z〉 and 〈y〉 in the Middle Ages to write sounds
that developed in this language that did not exist in Latin. They are used now to
represent sounds that are quite different from the ones these letters
represented originally. The letter 〈z〉 represents the sound [θ] in Spain and [s] elsewhere.
As for the letter 〈y〉, it has been appropriated to represent the consonant sound [j] or [ʝ] (see Chapter 7).

As
for the digraphs, many English words have the 〈ph〉, 〈th〉, 〈ch〉, and 〈rh〉 digraphs,
each representing a single sound, not two, as in the words physics, theory,
chemistry, and rhyme.
These words ultimately come from Greek and those letters in English words stem ultimately
from the mentioned transliteration of Greek words in Latin. Spanish, on
the other hand, did away with these Greek influenced spellings in the 18th
century. This explains why they cognates of these English words in Spanish have
no h in them: física, teoría, química, and rima.

Again,
the way these letters and digraphs are pronounced in English is not necessarily
the same way they were pronounced in Greek or in Latin. Take the digraph 〈ph〉, for instance. In English,
it represents the same sound as the letter 〈f〉, which is [f] in the
phonetic alphabet. In Latin, it represented the sound [pʰ], as aspirated p, i.e. the sound of the letter 〈p〉 in the English word pan [ˈpʰæn] (cf. Sp. pan [ˈpan], with unaspirated p). (The reason for this difference is
that the letter Φ (phi) came to be pronounced [f] in Greek at a
later time.) Also,
as we mentioned, some of these letters and digraphs have come to be used for
native English words that have no connection to Greek. The possible sounds of these
letters and digraphs have in modern English is summarized in Table 92.

Letters

Sounds

Sample words

〈ph〉

[f]

photograph

〈th〉

[θ]

cloth

[ð]

these,
other

[tʰ]

Thomas

〈ch〉

[kʰ]

character

[ʧ]

church

〈y〉

[j]

yes

[i]

happy

[ɪ]

myth

[aɪ̯]

my

〈z〉

[z]

zoo

Table 92: Sounds of the English letters y and z and the digraphs with h

As
we can see, the 〈th〉 digraph can represent three different sounds in English: the
one in cloth (the IPA symbol for this sound is [θ]), the one in clothes
(which, as we saw in Chapter 7, is a different sound, [ð],
the voiced counterpart of [θ]), and occasionally the one in Thomas,
which is identical to the sound of the letter 〈t〉 all by itself ([tʰ] in IPA).
It is this latter one that is most like the sound the Greek inspiration for
this digraph had. The use of 〈th〉 to represent the other two sounds is an
invention of French scribes after the 11th century and which replaced the
perfectly good letters that Old English had to represent those sounds.

Finally,
the 〈ch〉 combination can stand for two different sounds in English. The first
one is the one it has in the words chin or chap, IPA [ʧ]. The other one is the one it has in the words school,
character, Christ or Michael,
which is identical to the sound of the letter 〈c〉 in care or the letter 〈k〉
in kid, namely the sound of the phoneme /k/, which is usually aspirated
[kʰ].
Only the second of these sounds is anything like the original sound that the
Romans set out to represent with the digraph 〈ch〉. The former sound is one that
this digraph has is one that did not exist in Latin or Greek but existed in
Romance languages and English and the 〈ch〉 digraph was pressed into service to
represent it.

What
is the deal with these letter combinations? Why are they the way they are and why
do they represent the sounds they do? And what is the deal with that 〈h〉, that singular
letter which in isolation is sometimes pronounced—as in hair—and sometimes
not—as in honor, and which combines with 〈p〉, 〈t〉, 〈c〉 to form totally different
sounds? We will need to learn a bit of history of Greek and Latin to sort these
questions out.